Rates of Abnormal Aldosterone/ Renin ratio in African‐origin compared to European‐origin patients; a retrospective study

Abstract

Introduction

The aldosterone/ renin ratio is the initial screening test for primary hyperaldosteronism (PHA), but little data exists regarding ethnic variations in this.

Methods

Following clinical observation of a high prevalence of abnormal ARR in patients of African origin, we retrospectively reviewed all ARR measurements in a single centre over 10 years. Rates of hypokalaemia, intraventricular septal thickness (IVS, by echocardiography) and adrenal imaging were recorded when available.

Results

ARR was available in 1473 patients, and abnormal in 374 (25.4%). Abnormal ARR was observed in 305/ 1349 (22.6%) of European‐origin and 69/ 124 (55.6%) of African‐origin patients (p<0.001). Among those with abnormal ARR, hypokalaemia (<3.5 mmol/l) was documented on at least one occasion in 171/ 305 (56.1%) European‐origin and 43/ 69 (62.3%) African‐origin patients (p=0.35). Median (range) IVS was 1.57 (0.78 ‐ 2.80) cm in African‐origin and 1.20 (0.69 ‐ 2.18) cm in European‐origin patients (p<0.002); IVS did not correlate with aldosterone or ARR however. Adrenal adenoma was identified in 41/170 (24.1%) of European‐origin and 4/29 (13.7%) African‐origin patients (p=0.15), while hyperplasia was identified in 35/170 (20.5%) of European and 8/29 (27.5%) African patients (p=0.39).

Conclusion

In summary, ARR was abnormal in 55.6% of African‐origin patients screened at an Irish hospital. Rates of hypokalaemia were similar between European‐origin and African‐origin patients. These findings have implications for the use of current screening guidelines for ARR in African‐origin patients and also for the mechanistic role of aldosterone in hypertensive complications in African‐origin patients.

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